Bangladesh's "mystic minstrels" have long been dismissed as hippies and even attacked and killed after being branded heretics in the Muslim-majority country.
According to their leaders, Bangladesh's minstrels, known as Bauls, are growing in popularity, even attracting members of the rising middle class with their ethos of inclusion and rejection of consumerism.
"More and more people are drawn to Baul philosophy and its humanism despite the attacks and daily humiliation," said Mohammad Aynuddin, 35, an English teacher at a state school who describes himself as a Baul enthusiast.
Many ascetic Bauls renounce the modern world and travel on foot from town to town singing and begging alms, staying at ashrams, but have no fixed address. Others choose to remain in their homes, but live a quiet, secluded life of music and worship.
Strongest in west Bangladesh and across the border in India's West Bengal, the sect's philosophy is a mix of Hinduism and Sufism rather than one specific religion -- angering some Islamic hardliners.
Although police are still investigating, the professor's son and his colleagues believe both moves enraged religious fanatics.
In August, Muslim villagers also attacked a group of wandering Bauls, hacking off their beards and hair and forcing them to recite Islamic prayers, according to the Daily Star newspaper.
But such attacks failed to dent the mood recently at Lalon's shrine in a remote western village, where sect members new and old, gathered to mark the 124th anniversary of the singer's death.